The Caterpillar D9 is a large track-type tractor (commonly referred to as a bulldozer) designed and manufactured by Caterpillar Inc. The D9, with 410hp of gross power and an operating weight of 53.8 tons, is in the upper end of Caterpillar's track-type tractors, which range in size from the D3 (70hp, 8.1 tons), to the D11 (850hp, 124.3 tons). The size, durability, reliability, and low operating costs has made the D9 one of the most popular large track-type tractors in the world, with the Komatsu D275A as one of its most direct competitors.
The D9's primary working tools are the blade, affixed to the front and controlled by 4 hydraulic arms, and the optional ripper, which can be attached to the back. The blade is mainly intended for earthmoving and bulk material handling: pushing up sand, dirt and rubble. It also can be used to push other heavy equipment such as earthmoving scraper pans, and in military applications, main battle tanks. The rear ripper is intended for use in loosening rockey ground and ripping out larger stones. It can also break frozen ground.
The D9 has undergone several generations of engineering enhancements. The current version is the D9R but the older models such as the D9N and D9L are still common. The L, N and R models of the D9 are visually very similar, differing primarily in the design of their internal systems.
The size and weight of the larger track-type tractors dictate that they are used primarily for major projects. The D9 is most commonly found in use in construction, forestry, mining, waste, and quarry operations.
Caterpillar Inc. does not manufacture a military version of the D9 per se, but the same attributes that make the D9 popular for major construction projects make it desirable for military applications as well, and it has been found to be of particular utility by the Israeli Defence Force (IDF).
Armored bulldozers are a standard tool of Combat engineering battalions, and the IDF has gained some notoriety for their use of armored tractors in the Al-Aqsa Intifada , Operation Defensive Shield, and their involvement in the demolition of orchards and residences and the consequential death of Rachel Corrie.
The armored D9, as developed and modified by the IDF, provides armor protection to the external hydraulics and operator cabin. The operator is protected by bulletproof glass to protect against sniper fire. The fitted armor package adds roughly 10 additional tons to the weight to a so-equipped D9. Like many customized packages, individually modified D9s may be found with disparate features, such as crew-operated machine guns, smoke projectors, or grenade launchers.
The Israeli Combat Engineering Corps are using the D9 for a wide variety of engineering tasks: digging moats, clearing terrain obstacles and openning routes to AFVs. The D9's have also been used to clear landmine fields and booby-trapped areas. The heavy armour installed by the IDF allows the D9's to work under heavy fire in dangerous battle-zones. The Israeli armor kit proved itself well, as no D9 operator was killed during the 3-year long al-Aqsa Intifada.
The Israeli armored D9, a.k.a Duby (lit. bear) has been used in standoff situations with armed Palestinians barricaded in buildings and rigged them with explosives and booby-traps. In order not to risk Israeli soldiers, the D9 shook the house until the occupants surrendered and then razed the structure in order to detonate and bury any explosives inside. This method was also employed (with great success) in Jenin after 13 Israeli soldiers were killed in an ambush. In Hebron, the IDF used the armored D9 to stop the local Hamas leader, Bassal Qawasameh who was killed by the collapsing house after shooting at the D9 (photo from this incident).
Both military armored D9s and civilian non-armored D9s are employed by Israel's Ministry of Defence in the building of the Israeli security barrier. Their main application in the project are earthmoving and soil-leveling, making path for the security fence and digging trenches in front of it.
The United States Army has purchased several armor kits from the IDF and used them to produce similarly equipped D9s. These have been used to clear destroyed vehicles from roads, to dig moats, erect earthen-barriers and construct field fortifications. It was also used to destroy a house which hosted snipers who shot at an American base (similar to the Israeli usage). There were some reports about the use of large bulldozers against Iraqi trenches during the first Gulf War.
The Israeli armoured D9 bulldozer:
Military usage
Further references - Information and Pictures
Military D9 bulldozer:
Civilian D9 bulldozer:
